FDA Expands Approved Uses of Pfizer Drug to Include Childhood Leukemia

Rare Daily Staff

The U.S. Food and Drug Administration expanded the approval of Pfizer’s Bosulif to include pediatric patients 1 year of age and older with the rare blood cancer chronic phase chronic myelogenous leukemia that is newly diagnosed or resistant or intolerant to prior therapy.

Bosulif is an oral, once-daily, tyrosine kinase inhibitor, which inhibits the Bcr-Abl kinase that promotes CML. It is also an inhibitor of Src-family kinases. In the United States, the FDA first approved its use in adults in 2012.

The efficacy was evaluated in the BCHILD trial, a multicenter, nonrandomized, open-label trial conducted to identify a recommended bosutinib dose in pediatric patients with chronic phase chronic myelogenous leukemia that were newly diagnosed or resistant or intolerant to prior therapy, to estimate the safety and tolerability and efficacy, and to evaluate bosutinib pharmacokinetics in this patient population. The trial enrolled 28 patients.

The major efficacy outcome measures included major cytogenetic response (76.2 percent), complete cytogenetic response (71.4 percent), and major molecular response (28.6 percent) The median duration of follow-up was 14.2 months.

The most common adverse reactions in pediatric patients (20 percent or greater) were diarrhea, abdominal pain, vomiting, nausea, rash, fatigue, hepatic dysfunction, headache, pyrexia, decreased appetite, and constipation. The most common laboratory abnormalities that worsened from baseline in pediatric patients (≥45%) were increased creatinine, increased alanine aminotransferase or aspartate aminotransferase, decreased white blood cell count, and decreased platelet count.